The following maneuvers aren’t required on the private or sport pilot practical test. You’ll do the rectangular course, S-turns across a road, and/or turns around a point. (See Chapter 28.) They are given here for your information in case you and your instructor want to do some more complex wind drift correction.
Figure 16-4. The views from the cabin of a high-wing airplane at points 1, 3, 5, and 7 in Figure 16-3. The pond would help you know the wind direction (see Figure 18-2).
Chapter 16 / Postsolo Precision Maneuvers 16-5
Figure 16-5. Shallow around-pylon eights. This maneuver is a more complicated version of turns about a point.
that at points 3, 4, and 5 the airplane is crabbed in the turn. Point 6 has the shallowest bank and points 7, 8, and 9 require crabbing. When point 10 is reached (or point 2 again), the airplane is rolled into a turn in the opposite direction and the second pylon is used (points 11, 12, etc.). Not only should each circle be of con-stant radius, but both should be the same size. One of the common errors students make is to have a too-wide turn on one pylon and a too-narrow turn on the other.
Because of this tendency careful planning and orienta-tion are needed to get back to the spot exactly between the two pylons. You may repeat the pattern any number of times, but usually four or five are the maximum done without a break.
The blacked-out ellipse in the center of the illustra-tion might be called the “zone of confusion” because, even though the circles are supposed to be tangent, it’s impossible for an airplane to be rolled from one turn to the other instantly. So in actual practice they can’t be tangent, but you should make them as near tangent as safely possible.
Some common errors are:
1. Poor pylon picking (which will be covered shortly).
2. Coordination problems (slipping or skidding).
3. Altitude problems. The altitude should be the same as used for turns around a point and kept constant.
The usual problem is a tendency to climb as the airplane is rolled from one bank to another, and then lose altitude as the new turn (steep bank) is established.
4. Orientation loss, or “losing” a pylon. You may con-tinue well on past the point to roll in for the oppo-site turn. If you do this, you could make another 360° turn around the pylon, attempting to divert the attention of the instructor (or check pilot) by point-ing out objects of local interest as you go around.
(But you won’t get away with it.)
5. Nonsymmetrical circles — the turn around one pylon steep, the other shallow. This, too, can usu-ally be attributed to losing the other pylon as well as losing the center point of the pattern (point 2 or 10 in Figure 16-5).
6. Having too large an eight; the airplane is too far from the pylons and very shallow banks are required.
Steep Eights
Figure 16-6 shows the steep around-pylon eight maneuver. The turn pattern is closer to each pylon, and a straight leg is used to get set up for the other pylon.
This maneuver uses wind drift corrections in straight
16-6 Part Three / Postsolo Maneuvers
flight and a turn. You’ll have to plan the roll-out from one pylon so as to have the proper drift correction set up for the leg to the other pylon.
Note the steps at the following points in Figure 16-6:
Point 1. The airplane is in a position to enter the maneuver.
Point 2. Drift correction is set up in the straight leg.
Point 3. When the proper radius is reached, a turn is set up. Points 3 and 9 will require the steepest banks in this maneuver since the groundspeeds will be greatest at these positions.
Points 4–9. The bank is varied to maintain a con-stant radius. As point 9 is approached, the airplane is rolled out to set up the proper crab angle, points 10 and 11, to be at the required radius at point 12. This loop of the eight uses the same principle as the first.
The four angles indicated by the two A’s may be those desired by the instructor. Later, you will pick the pylons and set the maneuver up so that each of these angles will be 45°. (You can figure that the steeper the bank around a given pair of pylons, the smaller these angles will be.)
Figure on encountering the same errors as listed for the shallow eights plus a couple that would especially apply to this maneuver:
1. The turn in the entry may be too soon or too late, making the first loop too tight or too wide. You’ll find that at first you may take several patterns for each eight before settling down.
2. Problems during the straight portions of the maneu-ver — poor wind drift correction so that the airplane is not at the proper distance from the pylon as the turn is started.
Another pylon should be selected if the “back-to-back” idea (no straightaway) is used for steep and shal-low eights (Figure 16-7).
The principles involved are the same as for the other wind drift correction maneuvers discussed earlier. The turning portions of the eights follow the theory shown in Figure 16-3 — the airplane is crabbing in the turn.
The straight flight parts use the principles you learned when you first flew parallel to a road, correcting for a crosswind.
Figure 16-6. Steep around-pylon eights. Wind drift directions in both turning and straight flight are needed in this one.
Figure 16-7. You’ll need an extra pylon if you plan to fly both steep and shallow around-pylon eights “back-to-back.”
(Or you could pick an entirely new pair if you want a break.) A and B are the pylons for the shallow eights; A and C would be used for the steep ones.
Chapter 16 / Postsolo Precision Maneuvers 16-7
Figure 16-8. Picking pylons. Points beside a road are best for keeping your orientation. If there is no good reference exactly between the pylons, you should find the center with relation to some object, such as the tree shown here.
Figure 16-9. The constant-radius spiral.
The eights are more complicated than turns around a point because you have another pylon to consider and must be planning your transition from one to the other, even while maintaining a constant radius around one pylon. It’s easy to lose that other pylon by getting too involved in the one you are working with. It makes for a sinking feeling on a check flight when you roll out and don’t see anything that looks like the other pylon you selected earlier. Picking your pylons is very impor-tant; isolated trees near roads or other outstanding land-marks are good references (Figure 16-8). Choosing one of several trees in a large field can lead to results you might imagine.
These maneuvers are done at the same altitude as you used for the other wind drift correction exercises.
The Perplexing Problem of Proper Pylon Picking Probably one of your biggest problems is finding pylons the proper distance apart and oriented perpen-dicular to the wind. Students have gone on pretty good cross-country flights looking for pylons that were “just right,” while the instructor or check pilot grew restless in that right seat. A good method of picking pylons is to fly crosswind, looking to the downwind side. As soon as a proper pair of pylons is spotted, the airplane can be turned downwind to enter. Picking pylons beside a road helps a great deal in orientation. (Pylons don’t have to be trees, they can be other immobile objects;
one student picked a cow for one and, needless to say, the pattern was affected as the animal walked across the pasture. An automobile that drives off is also con-sidered a poor choice in most quarters.)
16-8
Spirals (Constant-Radius Descending Turns)
This is a maneuver that uses the wind drift correction skills you learned in turns around a point; in this case, however, you’re descending with power at idle (Figure 16-9). The practical aspect is that with practice you can spiral down around a particular point to set up a traffic pattern in the event of a power loss at altitude. (Fig-ure 18-3 shows the idea also.) You’ll get some prac-tice with this during your pre- and postsolo dual when the flight instructor gives you simulated high-altitude emergencies.
The spiral is a little more difficult than turns around a point because the airplane will be getting closer to the reference as you descend and the perspective will be changing. (The bank is steepest when flying directly downwind and shallowest when headed upwind, as discussed in turns around a point.) Hold the maximum bank to 40°.
The main problem in a spiral is that the airspeed may tend to get away from you — the usual error is to be too fast. Hold the airspeed to within ±10 K of that desired.
17-1
Procedure
1. Start the takeoff at the extreme end of the runway.
Set the flaps as recommended by the manufac-turer. Hold the wheel back and smoothly open the throttle.
2. As soon as you are certain the engine is developing full power, and the plane is accelerating properly, proceed with a tail-low takeoff. This is to let the plane get into the air sooner than would be the case if the airplane is “held on.” The plane will acceler-ate faster when airborne because of the lesser drag of the air. Don’t try to rush the process, because this will slow the takeoff as explained in “Normal Take-off” (Chapter 13). The attitude of the plane during the takeoff will naturally vary among airplanes.
3. The plane will lift off when the minimum flying speed is reached.
Some pilots suggest that the airplane should be held on the ground until VX (the max angle of climb speed), but this can cause two possible minor problems: (a) If the field is rough, this can be hard on the landing gear; if the surface is soft or con-sists of taller grass, you’ll take a lot of room to get VX. (b) For some nosewheel airplanes, a shimmy
Figure 17-1. Exaggerated view of maximum angle climb (1) versus maximum rate of climb (2).
Now you’ve done it! You’re a victim of that old tried and true aviation saying, “You can land a plane in places where you can’t get it out.” The field seemed short when you landed, and now the wind has died and things look pretty grim. There are some 50-foot trees at the other end of the runway that you’ll have to get over.
A special type of takeoff is needed here. (Or maybe you shouldn’t take off.)